Arc light



'7 Sheets- Sheet 1.

(No Model J. J. WOOD.

ARC LIGHT.

No. 426,405. Patented Apr. 22, 1890.

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(No Model.) 7 Sheets-Sheet 2.

J. J. WOOD.

ARG LIGHT.

No. 426,405. PatentedApr. 22, 1890.

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(No Model.)

ARG LIGHT.

No. 426,405. Patented Apr. 22, 18.90.

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J. J. WOOD.

ARG LIGHT.

No. 426,405. Patented Apr. 22, 1890.

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(No Model.) 7 Sheets-'Sheet 6.

J. J. WOOD.

. l ARG LIGHT. No. 426,405. Patented Apr. 22, 1890.

, ;is-A H x: i' A l M V INVENTOR: W'lTNESSES: i W %i g %w @MU x By lzz'sAomeys, ua m UNITED STATES PATENT OFFICE.

JAMES J. lVOOD, OF BROOKLYN, NEXV YORK.

ARC LIGHT.

SPECIFICATION forming part of Letters Patent No. 426,405, dated April22, 1890.

Application filed November 8, 1889. Serial No. 329,675. (No model.)

To all whom 't may concern.-

Be it known that I, JAMES J. lVOOD, a citizen of the United States,residing in Brooklyn, in the county of Kings and State of New York, haveinvented certain new and useful Improvements in Electric Are Lamps, ofwhich the following is a specification.

This invention relates to both single and duplex are lamps, the completeinvention being embodied in a duplex lamp.

The invention includes improvements in the regulatin g or feedingmechanism for feeding down the upper or positive carbon holder, incut-out devices, in means for insulation, in carbon-clainps, in meansfor transferring the feed from the first to the second earbon-holder, ina duplex lamp, and in various accessory devices and details ofconstruction.

In respect of the feeding mechanism, the lamps provided by my presentinvention are of that class having a rack-and-pinion feed, alifting-magnet in the main circuit being provided to strike the are, anda feedingmagnet in a shunt around the are being arranged to act inopposition to the main-circuit magnet, and thereby to tilt thearmaturelever from which the carbon-holder is hung through the medium ofthe rack-and-pinion connection, this tilting movement serving to releasethe feeding-gear and permit the carbon-holder to descend at a deterninedspeed until by the shortening of the arc and the weakening of theshunt-magnet the opposite tilting novement of the lever arrests thefeed.

My present invention is most directly an improveinent, or series ofimproveinents, upon lamps of the construction shown in the followingpatents granted to me, namely: `No. 257,800, dated May 9, 1882, forelectric-light regulator, and No. 384,817, dated June 19, 1888, for arclamps, (relighting cut-Outs.)

Figure 1 of the accompanying drawings is a front elevation, on a smallscale, of my new single lamp; and Fig. 2 is a similar view of my dup lexlanp. Figs. 3 to 15, inclusive, are views on a larger scale, showing theinternal construction of the single lamp; and Figs. 16 to 21, inclusive,are views showing the dupleX lamp. Fig. 3 is a side elevation-of thelamp meehanisn viewed from the left side, the tubular shell of theinclosing-case being in vertical mid-section. Fig. 4 is a verticalmid-section viewed in the same direction as Fig. 3. Fig. 5 is a rearelevation of the mechanisn partly in vertical section on the line 5 5 inFig. 6, the top part of the case being in section on the line 5 5therein. Fig. 6 is a horizontal section on the line 6 G in Fig. 5. Fig.7 is a fragmentary vertical section on the plane of the lines 7 7 inFigs. G and 9, showing the switch an d binding-postand theirConnections. Fig. 8 is a fragmentary section through the roof-platecutin the plane of the line 8 8 in Fig. 9. Fig. 9 is an inverted plan ofa fragment of the roof-plate, showing the switch and final cutout. Fig.10 is a fragnentary elevation, looking in the same direction as Fig. at,of the feeding-spindle and elutch. Fig. 11 is a dianetrical section ofthis spindle with its pinion, gear, and clutch cut on the line 11 11 inFigs. 6 and 10. Fig. 12 is a vertical mid-section of the lower part ofthe lamp, showing the negative-carbon holder, globe-holder, and ash-cup.Fig. 13 is an invented plan of the globe-holder with the ash-cupremovcd. Fig. 14 is an inverted plan of the ash-cup detached,and Fig. 15is a side elevation thereof. Of the views illustrating the dupleX lamp,Fig. 16 isa vertical section in the plane of the axes of thecarbon-holders, the plane being denoted by the line 16 16 in Fig. 18.Fig.17 is avertical section cut through the mechanism in the plane ofthe first carbon-holder, as shown by the line 17 17 in Fig. 18. Fig. 18is a horizontal section cut in the plane of the line 18 18 in Fig. 16.Fig. 19 is a fragmentary vertical section, on a larger scale, in theplane of the axis of the feeding-spindle, as denoted by the line 19 19in Fig. 18. Figs. 20 and 21 are fragmentary vertical Sections in theplane of the line 20 21 in Fig. 19.

As my invention can be best understood by first examining theconstruction of the simpler form of lamp, I will first describe thesingle lanp with reference to Fig. 1 and Figs. 3 to 15, inclusive.

Referring to Fig. 1, it will be seen that the lamp is, in general, ofordinary construction, having a mechanisn case or box A, a pendentlooped frame B extending thence downwardly and terminating in aglobe-holder B', in which the usual glass globe is fastened, the lowerorIOO negative earbon pencil being carried in a negative-carbon holder C',fastened to the lower part of the frame within the globeholder, and theupper or positive carbon being carried by a carbon-holder orverticalsliding rod C, movable up and down through the center of themechanism case, and the portion projeeting above the latter being housedin a protecting-tube a, all in substantially the usual manner.

The feeding or regulating mechanism in the case A is in general ofsinilar construction to the mechanisms shown in my previous patentshereinbefore recited. The carbon-holder C is provided with rack-teethwhich engage with a pinion c, fixed on the terminal spindle b of afeeding gear ortrain, designated as a whole by the letter D, this trainbeing carried by an armature-lever E, which is fulerumed between pivotalscrews e e, Fig. 6, and is pivotally or otherwise connected to thearmature lf of two opposed electro-magnets G and H. The magnet G iswound With coarse wire and connected serially in the main circuit, beingcomnonly called the main magnet, while the magnet H is wound with fineWire, so as to develop a high resistance, and is conneeted in a shunt orderivation around the are, being commonly called the shunt-magnet. The.magnet G is-the fitting-magnet for lifting the uppercarbon holder whenthe oireuit is established through the lamp, and thereby Striking theare. The magnet H is the feeding or regulating magnet for causing theupper carbonholder to travel downwardly, in order to compensate for thewasting away of the carbons.

Preferably these magnets G and H are of the solenoid type, the armature-F which plays between then being of H shape, as hereto- 'fore, or, inother words, having essentially two U-shaped cores united so that theirlegs project in opposite drections and enter the respective solenoidcoils. Thus the two magnets act oppositely to each other, one strivingto move the armature in one direction and the other to pull it in theopposite direction. Thisis a well-known construction, as shown in nyprevious patents above referred to.

The armature-lever E is preferably made in the form of au open frame, asshown best in Fig. 6, being made at one end in. the form of an openrectangular ring, within which the horizontal portion or cross-bar ofthe armature F is placed, and the remaining pora tion of the frameextending forward between two uprights e' e', as shown in Fig. 6, towhich it is pivoted by screws c e. This portion of the lever is also anopen frame, and within it is mounted the feeding-train D, which iscarried by the lever. This train consists of the terminal pinion c onits spindle b, constituting one end of the train, and a stop-Wheel f,eonstituting the other terninal of the train, with any suitable numberof intermediate wheels and pinions for multiplying the motion impartedto the pinion b by the running down of the carbon-holder C incommunicating this motion to the stopwheel f, so that the latter shallrevolve at a conparatively high velocity. This train is mounted in thelever E and participates in the movements thereof, the spindles of thetrain being extended between the opposite bars of the lever-frame andhaving their jour-.

nals turning in these bars, as shown in Fig. G.

Beneath the stop-wheel f is an elastieallynounted stop-teeth g, forn'edon or carried by a leaf-spring g'. \Vhen the armature-lever E isretained in its normal or mid position, as shown in Fig. 3, thestop-wheel f stands so low down that its teeth encounter the stop g,which prevents its rotation, and the train D eonsequentlyremainsstationary. \Vhemhowever, the are becomes unduly long and its inereasedresistance diverts an inereased current through the shunt-coil H, theadded attraction of the latter draws down the armature and tilts thearnature-lever until the wheel f is raised sufficiently to clear itsteeth from the stop g, whereupon the carbon-holder C runs down until theare is restored to its nornal length, whereupon the lever E returns toits normal position and the train is again raised by the engagement ofthe stop with the stop-wheel.

To prevent the too rapid descent of the earbon-holder, the train isprovided with a retarding device consisting of a vibrating bar h,actuated by an escapement, the wheel 71 of which is fixed on the samespindle as the stopwheelf. This general construction of feeding train orgearing is already known in the art.

It will be observed* that the lever E is of the second class, in thatthe weight hanging from the pinion b is between its fulcrum c and thearmature F. The main magnet G is arranged over the armature and theshunt-nagnet Il beneath it, which is the eontrary of the constructionheretofore enployed by nie; hence the magnet G, in lifting the arnature,pulls upwardly on the lever and lifts the pinion Z) and carbon-holder Cbodily, without its pull thereby increasing the pressure borne by thefulcrum-screws e e, so that the movenent of the lever is accomplishedwith less friction and is more direct than heretofore, from which itresults in praetice that the lamp upon the turning on of the currentinstantly draws the are to full length instead of drawing at first onlya partial are and leaving it to burn to full length by the wasting awayof the earbons. The lever is extended on the opposite side of thefulcrum chiefiy to make room for the feeding-train D, and also for thepurpose of partially counterbalancing the lever. The stop-wheel f, beingcarried by the lever on the opposite side of the 'fulerum, is moved upand down thereby, in order to engage with and disengage from the stop g,which, by .reason of the location of the wheel f on this side of thefulcrum, is placed beneath the wheel, as shown. The furthercounterbalancing of the lever E is effected by a spring I, the tensionIOO IIO

of which is adjustable by means of a serew beneath it, which is securedto the lamp-case. By adjusting the tension of this spring the weight ofthe lever E and of the armature F, carried by it, can be more or lesseounterbalaneed, and thereby the sensitiveness of the regulatingmechanism to the attraction of the shunt-magnet H can be adjusted inorder to determine the length of are which the lamp shall maintain.

Heretofore the adjustment of the stop g to bring it into correetrelation with the stopwheel f has been eifected by bending itsspring-arm g'. The adjustment by this means is difficult, particularlywhen the stop is inaecessible by reason of its being located inside ofother mechanism. To facilitate this adjustment, I provide theconstruction shown in Fig. 4:, where the spring-arm g* is bentdownwardly at its fixed end and fastened to a base 2 provided with aserew c", the end of which presses against the spring shortly above itsfixed end. Ey screwing this screw inward the spring g' will be bent andthe stop g be raised, and by screwing it outwardly the stop Will belowered. The spring g' becones thus virtually an elbow-lever, the serewt" be- .ing arranged horizontally, in order to render it easilyaceessible by a screw-driver.

The armature-lever is connected to a dashpot J, of usual construction,in order to resist any sudden or rapid movements and prevent the efieetknown as pumping As heretofore constructed the lamp was liable to injuryin case the carbon-holders C were too forcibly pulled downward. Acareless or unskilled trimner would frequently hasten the descent of theratehet in trinming by pulling down on it instead of waiting for it tofeed dou-*nwardly ln so doing a heavy strain was thrown upon the pinionand delieate wheels of the feeding-train, and they were liable to beinjured. Furthermore, by reason of the feeding-t-rain being mounted in abox or eage carried by the armature-lever and having a parallel motion,this downward pull had a tendency to crowd the pinion foreibly into therack-teeth and derange the parallel-motion device, so that thecarbon-holder would either become jam med or would work with unduefriction, thereby deranging the operation of the lamp. Thesedifficulties are removed in my present lamp by neans of two features ofconstruction. Of these the first consists in the mounting' of thespindle Z) of the feeding-pinion c directly on the lever E, its journalsturning in bearings therein, which are provided at an invariabledistance from the fulcrum of the lever, so that the downward pull uponthe carbon-holder has no tendeney to thrust the pinion into therackteeth. The movement of the pinion due to the vibration of the leveris a movement in a very slight are, and by reason of the fact that thepinion is mounted in the same horizontal line as the fulcrum-axis thisare eX- tends in a dircction so nearly approximating a vertical linethat the movement of the pinion toward and from the rack isinsigniiicant and involves a less degree of looseness than the usualplay necessarily allowed for free intermeshing. There is hence nopossibility of the pinion being jammed or crowded into the rack by anydownward pull thereon.

The second and novel feature of construction consists in the provisionof a frietional connection between the pinion and the remaining portionof the train D, or at least between the pinion and the retardingescapementwleel h'. This frictional connection is best shown in Figs. 10and 11. Referring to these figures, the pinion c is fixed on the spindleb by a cross-pin, and the ratchet-wheelj is also fixed on this spindle,so that the pinion and the ratclet-wheel are connected fixedly together.

The usual ratchet-pawls j' j' are pivoted to a disk k', which is looseon the spindle, but which is necessarily turned with the pinion when thelatter moves in the dircction of descent of the carbon-holder; but whenthe pinion is turned in the opposite dircction by the lifting movenentof the carbon-holder (as is done before inserting a new carbon) thepawls yield and permit the disk k' to remain stationary. In frictionalcontact with this disk is the gear-wheel Z, by which connection is madewith the renaining part of the feedingtrain, and this wleel is pressedfrietionally against the disk 75' by aspring k, constructed, preferably,in the form of a disk or washer having four or other number of elasticarms pressing toward the wleel Z, and which is preferably made fast to aflange k connected to the pinion or spindle, so as to turn therewith,whereby the wleel Z is grasped frictionally betweenthe disk k' andspring or washer k, both of which are compelled to turn with the pinionwhen the carbon-holder O is descending. If the carbon-holder be foreiblypulled down, the pinion c, ratchet Wheel j, disk la', and washer will beeaused to rcvolve; but the wleel l, by reason of the resistance of thetrain, will be kept from revolving faster than the train is permitted toturn by its escapement-governor. The wheel Z then will remain 'elativelystationary, while the disk k' and spring 73 revolve on. opposite sidesof it. The frieiional engagement between these parts and the wleel Z ismore than sufficient to maintain the carbon-holder elevated, thefrictional clutch thus formed yielding only when the carbon-holder isforeibly pulled down. This friction-clutch as a whole is designated bythe letter K.

I will now describe the relighting cut-ou t. The Object of suel acut-out is, in case the lanp becomes extinguished by the arc being blownout by the wind or by either of the carbon pencils breaking off, totenporarilyshorteircuit the lanp until the feeding mechanisn has broughtthe carbons together again, and

thereupon to restore the normal circuit, so that the lamp shallautomatically relight itself.

My present invention provides an improved construction of the generalform of relighting cut-out claimed in my patent, No. 384,817, abovereferred to. The arnatu re F, although pivotally connected to thearmature-lever E, is nevertheless so mounted as to be capable of amovement beyond that of the lever. \Vhen the lever has been tilted tothe position shown in Fig. 4, it is stopped by the Striking of two legsor toes Z' against the top of the shunt-magnet H. The armature F isforned with pivot-pins m m on its opposite ends, conneeted to the leverE by resting in notchesm' m', as best shown in Fig. 3. These notchesopen downwardly, so that after the lever E is drawn down until stoppedby its toes l', if the attraction of the magu et still furtherincreases, it may draw the armatnre down still lower, thereby pullingits pivot-pins m partially out of the notches m', as shown in dottedlines in Fig. L. Normally the armature is held up with its pivot-pins inthe notches by the attraction of the main magnet, assisted, preferablyby a spring n, which is not strong enough to sustain the weight' of thearnature. This spring is best applied in the form of a flat leaf, asshown in Figs. 5 and 6, with its middle part fastened by a screw n' tothe top of the cross-bar of the armature and its opposite endsoverhanging and pressing down- \vardly upon the lever E, as best shownin Fig. 3. This spring might, however, be omitted. It is by means ofthis independent motion of the armature that the cut-out is operated.

The cut-out contacts, lettered, respectively, L and L', are carried bythe armature F and lever E, respectively. They are preferably made ofstrips of copper, the contact L being fastened to the armature by thescrew n' and extending upwardly and overhanging the contact L', as shownin Fig. 3. The latter contact consists of a strip of copper fastened to,but insulated from, the rear end of the arnature-lever F, as shown inFigs, 5 and 6, and connected by a Wire to the cut-out shuntcircuit M.This cut-out shunt--circuit includes resistance-coils N, wound onasbestus, as described in my said previous patent.

In the normal operation of the lamp the contact L stands well above thecontact L', as shown in Fig. 3. If, however, the arc is blown out orotherwise extinguished, the current through the shunt-coils H will begreatly augmented, thereby strongly exciting the shuntmagnet and drawingdown the armature F and lever E until the latter is stopped by its toesZ', and drawing down the arnature still farther until it is stopped bythe abutment of the contact L against the contact L', as shown in Fig.4. As soon as these contacts touch the shunt becomes closed and theentire current is short-circuited from the carbons and main magnet(which are in series,

as usual) and divides between the shunt-magnet and the cut-out shunt M.The interruption of the cireuit and extinguis'hment of other lamps arethus prevented. As soon as the regulating mechanism has brought thecarbons together again the circuit through the carbons and main magnetis re-established, and since this circuit is of low resistance aconsiderable portion of the current will flow through the main magnet,thereby energizin g it and causin g it to lift the armatu re, wherebythe contacts L L' are separated and the lover E is tilted upwardly,thereby lifting the carbon-holder and drawing out the arc again,Whereupon the lamp resumes its normal operation. The cut-out shunt M isof only sufficient resistance to insure the diversion through the mainmagnet, when the carbons come together, of a current strong enough tocause this magnet to act and separate the cut-out contacts, in order torelight the lamp.

In my previous construction of lamp a spring was employed to act uponthe armature and react upon the armature-lever, so as to tend to drawthe cut-out contacts together, and the main magnet in the normaloperation of the lamp held the cut-out contacts apart against thetension of this spring. When the are was extinguished or an abnormal arcoccurred, the abnormal excitation of the shunt-magnet, added to thetension of this spring, drew the cut-out contacts together, andthereupon, the current being shunted through the cut-outcircuit M, andthe shunt-magnet thereby shortcircuited and greatly weakened, thecut-out spring referred to was relied upon to hold the cut-out contactstogether. This spring would sometimes become Weakened or relaxed by theheat within the mechanism case, and the Weight of the armature, which inmy previous lamp tended to separate the cut-out contacts, would becomeeective to draw them slightly apart, so tha-t an arc would form betweenthem, thereby buring or melting them. By mypresent invention I employ nocut-out spring whatever-that is to say, no spring tending to hold thecut-out contacts together-and consequently there is no tendency toseparate them by reason of heat occurring within the mechanism case.Furthermore, the weight of the armaturc F is so disposed that it tendsto draw the contacts together instead of to separate them. The spring77,, which is enployed to partially overcome this weight, is so arrangedthat it tends to separate the cut-out contacts instead of to press themtogether, and consequently if this spring should be relaxed by the heatno separation of the cut-out contacts could oecur as a result thereof,because the relaxing of this spring would have the opposite tendencythat is to say, it would permit the attraction of the shunt-magnet todraw the contacts more firmly together. Thus my invcntion overcomes adificulty which heretofore occasioned frequently serious injury to thelanps.

IOO

IIC

TIS

I will now describe the final cut-out, by

which the lamp is automatically short-circuited when the carbons arefully burned out. Within the mechanism case I provide a contact springor arm O, which is electrically connected to the negative binding-postand projects at its free end nearly into contact with thepositive-carbon holder C, as shown in Figs. 8 and 9. The positive-carbonholder is provided with a pin 0', which when the carbon-holder reachesits lowest position descends against and presses slightly down thespring O, as shown in Fig. 8. The current then passes from thecarbon-holder C through this pin into the spring to the negativebinding-post, thereby short-circuiting the lamp.

- The hand-switch or cut-out, by which the lamp may be switched into orout of circuit by hand, is constructed very much as in my previouspatents. It has a handle P at the bottom of the mechanism case,connected to a vertical shaft or spindle p, extending up through thecase and serving as the support for the resistance-coils N, and havingfixed to its upper end a switch-arm p', which can be turned into contactwith an elastic-metal seat P'. This seat is fastened to the innerroofplate Q, which is of metal and in connection, as heretofore, withthe positive binding-post. The upper end of the shaft p is mounted toturn in a recess in the lower end of the negati ve binding-post R', asshown in Fig. 7, whereby the switch-arm p' is in electrical connectionwith the negative binding-post.

The positive binding-post R (shown in section in Fig. 5) is' in metallicconnection with the inner roof-plate Q, while the negative binding-postR' is insulated therefrom, as shown in Figs. 7 and 8. Thesebinding-posts are constructed with suspension-hooks 7" r, as heretofore,and these hooks are arranged with their bent portions in the samevertical plane as the center of the looped frame B, as heretofore.Instead, however, of arranging the binding-posts with their centers inthis same plane and directly under the bends of their hooks, thebinding-posts are arranged to one.

side of this plane, so that they are out of line with the hooks and sothat the connecting line-wires are brought behind the hooks and theirinterference or entanglement with the hooks and 'with thesuspension-loops of the hanger-board is thereby avoided.

The mechanism-case is constructed of an exterior portion which isinsulated from the circuit and of an inner portion or frame which is inelectric connection with the positive binding-post. This inner portionor frame is composed of the inner roof-plate Q at the top, of a baseplate or disk S at the bottom, and of three intervening vertical framesconsisting of the two frames e' e', before referred to, and a thirdframe 8 at the rear of the case, these three frames extending betweenthe upper and lower plates and fastened to them -by screws. Thecarbon-holder O slidcs through holes in the centers of the upper andlower plates Q and S, being guided thereby, as usual. The current isconducted to this earbon holder through these plates and through theusual copper springsa'. Beneath the bottom plate S is fastened a diskF', of insulating material, the periphery of which projects beyond thatof the plate S. The mechanism is inelosed and 'concealed by a tubularshell q, of sheet netal, the lower portion of which extends closeoutside of and somewhat below the insulating-disk F', so that it is heldin place by the latter. The upper end of this shell enters within apendent fiange q', formed on the outer top plate Q', and is held inposition thereby. To get access to the interior mechanism, this outershell q is dropped down onto the lower frame B. \Vhen pushed up intoplace, it is held there by two leaf-spring catches g (1 which take overthe insulation F' without touching the netal plate S. Their ends projectdownward sufliciently to be easily reached and pressed out by thefingers when it is desired to unfasten and drop down the shell. Theupper plate Q' is insulated from the lower top plate Q by two insulatingplates or washers 7' through which the respective bindingposts pass, theplates being mechanieally fastened together by these binding-posts,which are constructed to serve as fastening-bolts in the same manner asheretofore.

The plate Q is of considerably-smaller diameter than the shell q, sothat it remains out of contact with the latter, and is thereby insulatedtherefroin. The purpose of thus insulating the exterior portions Q' andq of the mechanism-case is to prevent the possibility of thetrimmerreceiving a shock therefrom. I also provide for insulating thelower frame B for the same purpose. This frame consists, preferably, ofa single casting, the opposite arns of which terminate at their upperends in two horizontal plates or crossheads s', connected by a cross-bar3 These cross-heads 5' are fastened against the bottom of theinsulating-plate F' by screws which are passed through them, butinsulated from them, and which screw into the plate S.

The electric connection with the negativecarbon holder O' is madethrough the mediun of an insulated wire t, which is connected within themechanism-case with the end of the 1nainmagnet coil G by a binding-ringt', as shown in Fig. 3, and extends thence downwardly through the bottomof the mechanism case, being insulated therefrom by aninsulating-bushing 25 and is carried down along one side of the frame B,in the manner shown best in Fig. 1, being fastened thereto at intervalsby small pins u' u', driven into holes in the frame and their ends bentdown over the Wire, so as to embrace it. This fastening is claimed in mypatent, No. 407,914, dated July 30, 1889. The lower end of the wire iscarried within the globe-holder B', as

IOO

shown in Fig. 12, and its end is conected in the ordinary nianner to theinsulated negative conduetor C'.

The ash-cup T, which is commonly placed beneath the lower-carbon holderto catch the carbon dust or ashes that falls from the carbons, isfastened to the globe-holder B' by asort of bayonet-joint, soconstructed, however, that the ash-cup is less liable than heretofore tocome loose and drop out. The ash-cup is constructed with a fiange a, asusual, and this flange has notches 1) formed in it. These notchesregister with lugs o', projecting inwardly from the lower part of theglobeholder B', as shown in Fig. 13. To fasten on the ash-cup, it isthrust up beneath the globe-holder and turned until these notchescoincide With the lugs. It is then pushed up to bring its fiange abovethe lugs, and it is then turned toward the right until its ribs u strikethe lugs and stop it. One of the lugs is shown in dot-ted lines at u' inFig. 15. The fiange u is formed With beveled teeth u on its under side,which present their abrupt faces toward the lugs o' when the ash-cup isin place, as shown best in Fig. l5.` If the jarring of the'lamp shouldtend to rotate the ash-cup in a direction to disengage it, the abruptfaces of these teeth would abut against the lugs and would preventfurther rotation, whereby the ash-cup is retained securely in place.

The carbon-clanp U, applied to the carbonholder C for clamping thepositive carbon thereto, is of novel construction. It consists, as shownbest in Figs. 4 and 5, of a carbongripping device of any usualconstruction, carried by a sleeve or hub w, which is swiveled on thelower end of the carbon-holding rod O, the axis of the sleeve w beingout of line with the axis of the carbon pencil, which is fastened in thegripping device. By reason of this eccentricity or want of alignment therotation of the'carbon-clamp on the rod C will cause the lower end ofthe positive carbon to describe a circle; hencc, it' the points of twocarbon pencils do not come into line one above the other, thepositivecarbon clamp may be turned in either direction to bring itscarbon into correct alignment with the negative carbon. The sleeve w isfastened on the rod O, so that it cannot fall off therefrom, by means ofa screw or 1 )l11 tu' ,the end of which enters an annular groove formedaround the rod C. A set-screw w is provided for clanping the sleeve'fast on the carbonholder when the carbons have been brought to thecorrect position. This construction of carbon-clam p is much sinpler than the adjustable clamps heretofore used, which are hung to thecarbon-holder rod by a ball-and-socket connection and have threeadjusting-serews for adjusting the clanp to different angles relativelyto the rod. \Vith that construction, if either one of these screws isleft loose the upper carbon is liable to be displaced laterally and toslip down past the lower carbon,

thereby deranging the operation of the lamp.

I will now describe the construction of the duplex lamp with referenceto Fig. 2 and Figs. 16 to 21. This lamp contains the same mechanism asthe single lamp, with only the addition of certain parts designed tohold the second carbon-holder out of action during the feeding of thefirst carbon and upon the consumption of the first carbon to throw thesecond carbon into feed. The mechanism is rearranged in some respccts toadapt it for cngagement with two carbon-holders in place of one.

The two positive-carbon holders C are distinguished by being designatedC' and C C' being the carbon-holder of the carbon which burns first, andC of the one which burns second. These carbon-holders extend through themechanism case on opposite sides of the center thereof, as is usual induplex lanps, their upper ends working in protecting-tubes a' and arespectively.

The rack-teeth of the earbon-holders cngage pinions c' and 0respectively, which are carried on the feeding-spindle b, but turnloosely thereon, being conneeted to it only through the medium of theusual ratchet-andpawl connections. The-ends of the spindle are hung inarms E' E', forming part'of the frame of the armature-lever E, which isto this extent modified in shape, and the longitudinal side bars of therear frame of which are drooped at E to make room for the spindle b andits attaehed wheels.

The weight of both the first and second carbon-holders is borne by thearniature-lever during all the time that the lanp is in operation. Whilethe first pair of carbons is burning the second carbon-holder 0 issuspended from the lever in such manner that it cannot be feddownwardly, a hile the first carbonholder O' is in engagenent with thefecding mechanism in the same manner as in a single lamp. lVhen thefirst pair of carbons is consumed and the first carbon-holder reachesthe linit of its downward novenent, it automatically disengages thesecond carbon-holder and enables it to feed down, after which the firstcarbon-holder langs inertly suspended from the lever. The lamp isfinally cut out by the switch O (shown in Fig. S) when the secondcarbon-holder reaches thelimitof its down- Ward movem ent.

The suspension of the second carbon-holder out of action during the timethat the first carbon-holder is feeding downward is accomplished bymeans of a ratchet-wheel :16, fastened to the second feediug-pinion 0 asshown best in Figs. 18 to 21, engaged by a pawl oc', pivoted to thearmature-lever E and pressed by aspring 2 so as to engage with theratchet- Wheel. This pawl yields to the rotation of the ratchet-wheel ocwhen the second carbonholder is pushed up, but thereupon imme- `diatelyengages, as shown in Fig. 20, and prevents the carbon-holder fromfeeding down. Meanwhile the feeding of the first carbon- IOO holderproceeds without interruption, the spindle Z) turning frcely within. thesleeve or hub of the pinion and ratchet-Whecl a'. During the fecding ofthe first carbon-holder the disk 70', carrying the pawlsj' of theratchetwheelj, rotates with the spindle, and these pawls ride freelyover the ratchet-wheel.

In order to throw the second carbon-holder into action, a :releasingdevice is provided for throwing up the pawla' to the position shown inFig. 21. This releasing device consists in the preferred construction ofa rock-shaft y, mounted in bearings on the lever E, extending from nearone carbon-holder to near the other and having two projecting arms orcranks y' and 1 The arm y' stands normally over the tail of the pawl03', as shown in Fig. 20. The arm 1 extends close to the firstcarbon-holder, and stands directly beneath a pin b' thereon. Thisrock-shaft 3 is tilted by its arm y', resting on the upper end of thepawl ca', which is raised by the action of the fiat spring 111 therebylifting the arms y' and y the movement being limited by the engagementof the pawl oc' with the ratchetwheel oc, as shown in Fig. 20. XVhilethe first carbon-holder is feeding the parts Stand-in the positionsshown in Figs. 19 and 20. Finally the pin b' encounters the arn ?f andtilts the rock-shaft, thereby throwing down the arm y' onto the tail ofthe pawl x', conpressing the spring y and disengaging the pawl from' theratchet-wheel ;17, as shown in Fig. 21. Thereupon the secondcarbon-holder C commences to feed downwardly and brings its carbon intocontact with the negative carbon beneath, While the arc is stillmaintained between the first pair of carbons, whereby 'the are istransferred to th second gair. The

first carbon-holder C' remains suspcnded from the lever Eby its pinb',resting on the arm In order to be able to disengage the pawl x" atwill, to enable the trimmer to pull down the second carbon-holdcr,(thereby making use of the friction-elutch K, before describech) or toenable the second carbon-holder to run down of itself to any position, apull-knob 5 is provided underneath the meehanisn case, as best shown inFig. 16, which is connected through a rod z" to-an ar'n 3 formed on therock-shaft y, so that by pulling down this knob the rock-shaft may betilted to the same effcct as by the pin b', thereby disengaging the pawlx'.

In order to prevent the second carbonholder being pnshed up so high asto bring its carbon-clamp U close against the under side of themeehanism case, and thereby to resist and prevent the lifting of thecarbonholder in order to strike the are, I provide a lever 2 (shown inFig. 16,) which, when the second earbon-holder is thrust fully up, willbe engaged and thrust back by its carbonclamp U, so that its lower armwillbe vibrated downwardly and will press down the knob z, and therebydisengage the pawl x'. When the second'carbon -holder is let go, it willfeed downwardly until it releases the lever ,e -tl1atis, until itreacles the position shown in Fig. l wlereupon the knob ,e beingreleased, the pawl x' will fall into engagement and prevent its furtherdescent. The second carbon-clamp U is then sufiiciently below the bottomplate of the case to admit of the upward play of the carbon-holders inorder to strike the are.

The second carbon-holder may be set. originally at any desired height inmy lamp. In other duplex lamps the second carbon-holder must besuspended in its uppermost position during the operation of the firstcarbon-holder.

In the operation of duplex lamps it does not always occur that bothpairs of carbons are completely consumcd, it being frequcntly the casethat the lamps are required to burn only long enough to consume thefirst pair and about half of the second pair. In such a case it isdesirable to utilize the remainder ol' the second pair 011 the ensuingnight; but to do this heretofore it has been necessary for the trimnerto remove the partially-burned carbons of the second pair and transferthem to the first carbon-holders and to put f ull-length carbons intothe second carbon-holdcrs; otherwise the light is' extinguished for amoment after the first carbons are consuned. This trouble is avoided bymy invention, which enables the partially-consumed carbons to be left inthe second carbon-holders and requires only that the firstcarbon-holders'bc supplied with new carbons.

Another advantage of my present invention is that it nakes no differencewhich pair of carbons lights first, so that less care is required intrinming the lamp. It' the are first Springs between the second pair ofcarbons, it Will burn without feeding until the first carbon-holderfeeds down and brings the carbons of the first pairinto contact;whereupon the are will be t'ansferred to the first pair of carbons.

My improved duplex lamp is also an improvement upon my previous (luplexlamp, in that it makes no difference which of the carbon-holders waslifted last. \Vith ny previous lamp the trimner had to be careful tolit't the first carbon-holder last, asotherwisc the lamp would beinoperative; but with my present lanp no carelessness on the part of thetrimmer, short of an injury to the lamp mechanisn or an improper settingof the carbon-pencils themselves, can render the lanp inoperative.

My improved duplex lamp may be modified by omittin g the ratchet-wheelna and applying the pawl directlyto the teeth of the pinion (3 to likeeffect; or, the pawl may be made to engage the teeth of the rack on theholder 0 instead. In these cases the pinion or rack will become theequivalent of the ratchet- Wheel x. The disengaging device night be asimple lever of the first class instead of the rock-shatt y. Thedisengaging device might be nounted on any other or stationary part IIOinstead of on the lever E, but wit-h less advantage. The mechanism maybe otherwise modified, as may be readily inferred by those skilled inthe art.

In both the single and duplex lamps the two members of the looped frameB and the annular globe-holder B', with its cross-bars for supportingthe central hub, to which the negative-carbon holder is fastened, areall cast in one piece. This I believe to be a novel construction inelectric lamps having looped frames, it having been customary heretoforeto make the globe-holder separate from the members of the frame and tofasten it thereto by screws.

I claim as my invention the following defined novel features andcombinations, substantially as hereinbefore specified, namely:

1. The combination, with a carbon-holder having rack-teeth, anarmature-lever, a feeding-train carried by said lever, terminat ing in apinion meshing with said rack and having a toothed stop-Wheel, and astationary stoptooth arranged to engage said stop-Wheel when the latteris moved toward it by the lever, of an elastic arn or spring on whichsaid tooth is formed or mounted, extending approximately horizontally,bent at right angles, and fastened, and an adjusting-screw arrangedhorizontally to bear against said elastic arm, whereby by the horizontaladjustnent of said screw the stop-tooth may be raised or lowered, andthereby adjusted relatively to the stop-Wheel.

2. In an are lamp, the combination, with a carbon-holder havingrack-teeth and a feeding-train for feeding down the holder, including afeeding-pinion engaging with the rack and a retarding device forgoverningtherate of feed, of a friction-clutch interposed between saidpinion and retarding device, whereby when the carbon-holder is forcibly`pulled down the said clutch will slip and avoid injury to thefeeding-train.

3. In an are lamp, the conbination, with a carbon-holder havingraek-teeth and a feeding-train, including a feeding-pinion, engagingsaid rack, and a retarding device, of a friction-clutch consistin g of agear-wheel on said train, connected through its gear-teeth with theretarding device, a disk connected to the feeding-pinion, so as torotate therewith when the carbon-holder descends, and a spring forpressing said gear-wheel and disk into frictional contact.

4. In an arc lamp, the conbination of an armature-lever, a main magnetabove the lever and a shunt-magnet below it, an interposed armatureconnected to the lever through a loose pivotal connection adapted topermit of the armature being drawn down by the shunt-magnetindependently of the lever, and cut-out contacts carried by the leverand armature, respectively, the one carried by the armature beingarranged over and standing normally out of contact with the one carriedby the lever, whereby an abnormal excitation of the shunt-magnet drawsdown the armature and brings said contacts together and the weight ofthe armature tends to hold them together.

5. In an are lanp, the combination of an armature-lever, a main magnetabove the lever and a shunt-magnet below it, an interposed armatureconnected to the lever th rou gh a loose pivotal connection adapted topermit of the armature being drawn down by the shunt-magnetindependently of the lever, a spring tending to lift the arnature andreacting against the armature-lever, and a cut-out contact carried bythe arnature and lever, respectively, and arranged to be closed togetherby the attraction of the armature downwardly relatively to the lever andagainst the tension of said spring, whereby the weakening of said springby heat will have no tendency to separate the cut-out contacts.

G. In an are lamp, the combination of an arnature-lever, a main magnetabove the le'- ver and a shunt-nagn'et below it, an interposed armatureconnected to the lever through a loose pivotal connection adapted topermit of the armature being drawn down by the shuntmagnet independentlyof the lever, stops for limiting the drawing down of the lever, andout-out contacts carried by the lever and armature, respectively, thatcarried by the armature standing over the one carried by the lever andarranged when brought together by the attraction of the arnature by anabnormal eXcitation of the shunt-magnet to form stops for liniting thedownward movement of the armature.

7. In an are lamp, the conbination, with an armature F and anarnature-lever E, constructed as an annular frame to inclose thearmature and having notches open beneath engaged by pivot-pins on thearmature, of a spring n, for partly sustaining the weight of thearmature, consisting of a leaf fastened to the armature at its middleand having its free ends pressing downwardly on opposite sides of thelever.

8. In an are lamp, the eonbination, with the mechanism-case, thenegative binding-post 'passing through and insulated from the top of thecase, and the posith e-carbou holder C, having a pin 0' projecting fromit near its upper end, of a spring cut-out arn O, fastened to and ineleotric connection with the negative binding-post underneath the top ofthe case, and arranged with its free end projecting into the path ofsaid pin o' 'in position to be encountered thereby when the carbonholderreaches the end of its downward movement, and thereby to stop the latteryieldiugl y and short-cireuit the lamp.

9. In an are lanp having a mechanism-case and a frame extending thencedownwardly for the support of the lower-carbon holder, the positive andnegative binding -posts constructed with suspension-hooks arranged withtheir bends in the same plane as said lower frame, and the binding-postsdisplaced from IOO IIO'

ITS

said plane to the rear of the hooks, for the purpose specified.

10. In au electric lamp, the combination, with the globe-holder havingprojecting lugs, of 'an ash-cup having a notched fiange for engagingsaid lugs, formcd with beveled teeth, the abrupt faces of which arearranged to be presented to the lugs when the ash-cup is in place.

11. In an arc lamp, the combination, with a carbon-holdin g rod, of acarbon-clam p having gripping-jaws for engaging the carbon pencilarranged to hold the latter with its aXis out of line with the aXis ofthe rod and connected to the rod through the medium of aswivel-connection, whereby it may be rotated relatively to the rod.

12. In au are lamp, the combination, with a carbon-holding rod, of acarbon-clamp consisting of gripping-jaws arranged to hold the latterwith its axis eccentric to that of the rod and connected to the rodthrough the medium of a swiveled connection, whereby the carbonclamp maybe turned relatively to the rod, and with a set-screw for fastening itin any rotative position.

13. In a duplex lamp, the combination of the carbon-holders havingrack-teeth, feeding-pinions engaging therewith, an armaturelevercarrying said pinions, a feeding-train for regulating the feed, a pawlcarried by the armature-lever and adapted to prevent the feeding down ofthe second carbon-holder during the feeding of the first holder, and aprojection carried by the first carbon-holder and adapted at thetermination of the move- Inent thereof to throw said pawl out of actionand cause the second carbon-holder to feed.

14. In a duplex arc lanp, the conbination, with the two carbon holdershaving .Packteeth, of two feeding-pinions, an armaturelever carryingsaid pinions, a ratchet-wheel connected to the second feeding-pinion,and a pawl adapted to engage said wheel during the feeding down of thefirst carbon-holder, and thereby prevent the rotation of the secondfeeding-pinion.

15. In a dupleX arc lamp, the combination, with two carbon-holdershaving rack-teeth, of two feeding-pinions, an armature-lever carryingthem, a ratchet-wheel connected to the second feeding-pinion, a pawladapted to engage said ratchet-wheel to prevent the rotation of thesecond feeding-pinion during the feeding down of the firstcarbon-holder, a stop projection on the first carbon-holder, and amechanical connection between said stop projection and pawl, adaptedupon the termination of the downward movement of the first carbon-holderto communicate inotion to said pawl and withdraw it from saidratchetwheel.

16. In a duplex arc lamp, the conbination of the two carbon-holdershaving rack-teeth; two feedingpinions engaging said racks, anarmature-1ever carrying said pinions, a ratchet-and-pawl device adaptedto nornally prevent the feeding of the second carbonholder, arock-sha'ft having an arn adapted when rocked to disengage said pawl,and the first carbon-holder having a stop projection arranged when itreaches the limit of its downward movenent to encounter said rockshattand oscillate it in a direction to release said pawl.

17. In a duplex 'are lamp, the combination of the two carbon-holdershaving rack-teeth, two feedingpinions engaging said racks, anarnature-lever carrying said pinions, a ratchet-and-pawl device adaptedto normally prevent the feeding of the second carbonholder, a rock-shafthaving an arm adapted when rocked to disengage said pawl, and the firstcarbon-holder having a stop projection arranged when it reaches thelimit of its downward novement to encounter said rock-shaft andoscillate it in a direction to release said pawl, and means forreleasing said pawl by hand, consisting of a knob beneath themechanism-case, and a mechancal connection between said knob and therock-shaft, whereby the shaft may be oscillated from said knob.

18. In a duplex arc lanp, the combination, with the carbon-holdershaving rack-teeth, of feeding-pinions engaging them. a ratchet-andpawldevice adapted to normally prevent the feeding of the secondcarbon-holder, means, substantially as described, for releasing saidpawl when the first carbon-holder reaches the limit of its feedingnovenient, and a m echanical connection. operated by the lifting of thesecond carbon-holder to its extreme height to release said pawl and holdit released until the second carbon holder is dropped sufficiently toadmit of the Striking of the arc.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

JAMES J. \VOOD ICO

